package com.itheima.reggie.controller;

import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

@Slf4j
@RestController
@RequestMapping("/common")
public class CommonController {
    @Value("${reggie.path}")
    private String basePath;

    /**
     * 文件上传
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){
        //file是一个临时文件，需要转存到指定位置，否则本次请求后会删除临时文件
        log.info(file.toString());
        //原始文件名
        String originalFilename = file.getOriginalFilename();//abc.jpg
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));//.jpg
        //使用UUID重新生成文件名，防止文件名重复造成文件覆盖
        String fileName = UUID.randomUUID().toString();
        //创建一个目录对象
        File dir=new File(basePath);
        //判断目录是否存在
        if(!dir.exists()){
            //目录不存在则创建目录
            dir.mkdirs();
        }
        try {
            file.transferTo(new File(basePath+fileName+suffix));
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        return R.success(fileName+suffix);
    }

    /**输出流
     * 请求下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){

        try {
            //输入流，通过输入流读取文件内容
            FileInputStream fileInputStream = new FileInputStream(new File(basePath + name));
            //输出流，通过输出流写回浏览器，在浏览器显示图片
            ServletOutputStream outputStream = response.getOutputStream();

            response.setContentType("image/jpeg");

            int len=0;
            byte[] bytes=new byte[1024];
            while((len=fileInputStream.read(bytes))!=-1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
            outputStream.close();
            fileInputStream.close();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }

    }

}
